Home entertainment systems capable of playing back moving images as well as running game programs have been proposed. In home entertainment systems, a GPU generates three-dimensional images using polygons (see, for example, patent document No. 1).
Portable terminals available nowadays are provided with a display screen of an increasingly larger size and are capable of displaying high-definition images regardless of the type of an information processing device. The higher the definition of an image, or, the more information sought to be displayed in a single image, the larger the size of an image displayed. As a result, users are seen in daily scenes to move an area displayed on a screen regardless of the content displayed.
[patent document No. 1] U.S. Pat. No. 6,563,999
In a content in which a partial area of an image with a large size is displayed on a screen, the user may be lost as to where in the original image the currently displayed area is located. This may produce inefficiency in that the user may advance the display area, unaware of the fact that the display area has already reached an edge of the image or wander in a blank area that lacks information to be displayed, stressing the user as a result.